Human Dermis Harbors Distinct Mesenchymal Stromal Cell Subsets

Abstract

Multipotent mesenchymal stromal cells (MSCs) are found in a variety of adult tissues including human dermis. These MSCs are morphologically similar to bone marrow–derived MSCs, but are of unclear phenotype. To shed light on the characteristics of human dermal MSCs, this study was designed to identify and isolate dermal MSCs by a specific marker expression profile, and subsequently rate their mesenchymal differentiation potential. Immunohistochemical staining showed that MSC markers CD73/CD90/CD105, as well as CD271 and SSEA-4, are expressed on dermal cells in situ. Flow cytometric analysis revealed a phenotype similar to bone marrow–derived MSCs. Human dermal cells isolated by plastic adherence had a lower differentiation capacity as compared with bone marrow–derived MSCs. To distinguish dermal MSCs from differentiated fibroblasts, we immunoselected CD271+ and SSEA-4+ cells from adherent dermal cells and investigated their mesenchymal differentiation capacity. This revealed that cells with increased adipogenic, osteogenic, and chondrogenic potential were enriched in the dermal CD271+ population. The differentiation potential of dermal SSEA-4+ cells, in contrast, appeared to be limited to adipogenesis. These results indicate that specific cell populations with variable mesenchymal differentiation potential can be isolated from human dermis. Moreover, we identified three different subsets of dermal mesenchymal progenitor cells.

Epigenetic and in vivo comparison of diverse MSC sources reveals an endochondral signature for human hematopoietic niche formation

“…13,14 Initially, the term MSC was restricted to BM, but in recent years the definition has broadened to now include connective tissue cells from many sources such as UC blood (UCB), 15,16 WAT, 17 UC, 18 dental pulp, 3 skin, 19 and others. 20 However, functional equivalence in vivo and epigenetic characteristics of these cells have not been studied.…”

Adult Stem Cell Subsets from Adult Human Dermis

“…Human cells expressing CD146 derived from diverse sources have been shown to differentiate in vitro not only into osteoblasts, chondrocytes, and adipocytes [38] but also into hepatocyte-like cells [39] and smooth muscle [40]. CD271 is an epitope that was initially identified in situ in skin punch biopsies and characterized as a strong hMSC marker over adherent dermal cells [11].…”

“…Live cell staining and fluorescence activated cell sortingbased purification [11], and [C] 1:100 CD73:PE-Cy7 (BD Bioscience, 561258), CD90:PE antibody (BD Bioscience, 555596), and CD105: AlexaFluor 647 antibody (BD Bioscience, 561439) [17]. Samples were incubated for 30 min in the dark at 4ºC with gentle nutation.…”

“…Adult human dermal biopsies contain a variety of cells with discrete multipotent phenotypes [3][4][5][6][7][8][9][10][11], which are lost over extended culture periods [5]. The presence or absence of certain markers (CD73, CD90, CD105, CD146, CD271) associated with ex vivo multipotency appears to depend on factors such as biopsy procedure and expansion, cell density, culture conditions, and longevity of culture [5,9,10].…”

“…Among these cellular surface markers, the canonical surface markers 5'-nucleotidase, ecto (CD73) or NT5E, thymocyte antigen 1 (CD90) or Thy-1 and Endoglin (CD105), were initially described as unique for mesenchymal stromal cells, but have since been identified as distributed among diverse types of human cells including fibroblasts with some or no in vitro mutipotency [1,8]. Previous research in human adult adipose cells and human neonatal dermal derivatives suggest Melanoma Cell Adhesion Molecule (CD146) or MCAM [10] and nerve growth factor receptor (CD271) or NGFR [11], respectively, as putative candidate markers to isolate mesenchymal stromal-like cells from human adult dermal derivatives, which would enhance the ability of forming bone, cartilage, and fat ex vivo. In theory, adult multipotent dermal fibroblasts can be easily attained through a minimally invasive and relatively painless skin punch biopsy [12] and hMSC derivatives purified via cell surface markers for in vitro or in vivo clinical applications [9,13].…”